I live in a location where I have to turn straight onto a highway with no ramp and no acceleration lane (yeah I know it's a bit weird) and that means that during morning commute I have to make a hard 90 degree turn and then floor it to get to 90km/h asap so as to not obstruct any traffic. All my cars have been performance cars partially because of this interesting road construction choice as it makes quite a difference if you get to 90km/h in 4, 5 or 10 seconds in options you have to merge in.

Now the thing with Model S (owned a whopping 2 weeks) is that when I floor it after I turn straight it starts to fishtail above ca 50km/h until I release the accelerator around 100km/h. It's a smooth fishtailing with the rear just going left and right marginally, but I feel it strongly in the car. I keep the wheel centered and it disappears the moment I reduce the acceleration so it's only under hard acceleration. I'm using aftermarket wheels, but I'm not sure if that could be the reason here. The car was trailered from Tilburg to Tallinn and I've heard people claim the transport might screw up the alignment. As I'm still waiting for my TPMS set for the 19" wheels I thought to ask around here for recommendations what to ask them to check when I go to the tire shop. Not sure they have an alignment bench, but maybe there's something they can check visually if everything's to the specs.

Sorry I don't have a link but I remember reading something about torquing your lug nuts to spec, and checking the air pressures are matching. I also recall that alignment can play a significant role in fishtailing...if all else fails there is always the after market upgrade to a P+ - that worked for Dennis.

After putting on my winter wheels (Michelin X-ice Xi3s on 19" Rial Luganos), I had significant swaying under hard acceleration...the traction control indicator would flash like a strobe light. After a few hundred miles, this has calmed down considerably. This behavior was not there on the factory wheels, so I will chalk it up to deeper and more aggressive studless snow and ice tire tread patterns. I have kept a very close eye on the tire pressures, and my lugs are all at 175 N-M.

I have the same on a dry surface, but only since I switched to winter tires. Does not occur with the summer tires. Also after several hundred miles on the winter tires this "fishtailing" has become less noticeable and less frequent.

I have the same on a dry surface, but only since I switched to winter tires. Does not occur with the summer tires. Also after several hundred miles on the winter tires this "fishtailing" has become less noticeable and less frequent.

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how's your alignment/tire wear on your summer tires, have you measured it? maybe it appears to be getting better only because the new tread is getting worn down on the inside rear. so many folks have had alignment issues.

how's your alignment/tire wear on your summer tires, have you measured it? maybe it appears to be getting better only because the new tread is getting worn down on the inside rear. so many folks have had alignment issues.

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My money's on the alignment issue. Had the identical problem, alignment was completely FUBARed.

Now the thing with Model S (owned a whopping 2 weeks) is that when I floor it after I turn straight it starts to fishtail above ca 50km/h until I release the accelerator around 100km/h. It's a smooth fishtailing with the rear just going left and right marginally,

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Sounds like your MS is doing exactly what it should be doing. The MS has a 100% torque at 0 rpm. It is a rocket.

The P85 can spin the wheels at 35mph if you floor it with the stock 19" all-seasons. It's only going to be worse with the winter rubber and cold temperatures I'd imagine you have right now. So while the wagging sounds abnormal, spinning the tires probably isn't.

The P85 can spin the wheels at 35mph if you floor it with the stock 19" all-seasons. It's only going to be worse with the winter rubber and cold temperatures I'd imagine you have right now. So while the wagging sounds abnormal, spinning the tires probably isn't.

Same thing happens on my P85+, I had the alignment checked at the service center and it still happens. I think it is just the car's software not being too aggressive on stability control. I'd rather it do that than limit my ability to use the power.

I had alignment checked. All within specs. slight wear on inside of summer tires (rear) after 9000 miles. slight fishtailing on hard acceleration with winter tires. One way to avoid this is to accelerate more smoothly, but that's not quite as fun!

My P85 with it's 19" all-season tires on, fishtailed yesterday. I was 'mock' racing my buddy in his Jeep (just happened to pulled up to a light next to him). We take off from the line, not accelerating that quickly (neck in neck) just tongue-n-cheek, then I floor it at about 35 mph. I get a bit of fishtail as the backend breaks loose as I rocket up to what I'll call the speed limit.

I'm on the latest firmware 5.8 (just got a second 5.8 updated Saturday).

There's nothing wrong with a little oversteer. My complaint is more that there no way to totally disable the stability control if you want to enjoy some sideways fun. I've always been able to do this with every BMW I've owned. Balanced, high-power, rear-drive cars should be able to be steered with the throttle. They should also command respect. The throttle is not an on/off switch and should be applied smoothly and with careful consideration relative to steering angle, road conditions, tire temps etc. If you have driven a high hp performance car from the pre-stability control days you learned this pretty quick or ended up off the road. If you asked on a Porsche forum why you ended up sideways flooring on the throttle of a '77 930 out of a 90 degree turn you might get some pretty funny responses.

Now all this said, its worth checking your alignment based on all the toe-out misalignments people are experiencing.